First generation inflation systems for automotive airbag applications generally used a single gas generator to effect bag inflation. Typically, the gas generator was ignited electrically by use of a pyrotechnic detonator. Subsequently, multiple gas generators, which exhibit a relatively higher pumping ratio, were used as the primary gas source for such inflators. In addition, multiple gas generators provide improved inflator reliability upon the occurrence of cartridge or ignition failure. Moreover, multiple cartridges present a means to control inflator output for use in a crash adaptive system.
However, a problem exists in the use of multiple electrically ignited gas generators due to the relatively high energy requirement necessary to achieve simultaneous ignition and due to the use of multiple, bridgewire-type ignition squibs.